1. Field of the Invention
The invention generally relates to an indoor mobile wireless communication data measurement system and more particularly to an indoor signal property measuring device that utilizes a mobile personal computer connected to a receiver for measuring location specific wireless communication system signal properties and data network throughput properties within a facility and embedding the measured properties at the measurement location within a three-dimensional drawing of the facility stored in the computer.
2. Description of the Related Art
In recent years the use of wireless communication technology, such as cellular phone networks, has greatly increased. Moreover, it has become common to implement wireless communication systems within buildings or large facilities comprising several buildings. Examples of typical wireless communication systems are local area networks (LAN), wide area networks (WAN), or cellular phone networks such as PBX, or local loops. Due to the increasingly diverse applications of wireless communication systems, system designs have become increasingly complicated and difficult to implement.
Common to all wireless communication system designs, regardless of technology, size or scale, is the need for measurement data at some point in the design process. Whether in the initial design stage or the final verification stage, no wireless communication system is implemented without the input of measurement data. However, measurement acquisition in in-building environments is much more tedious and time consuming than in the macrocellular environment where measurement acquisition is carried out using Global Positioning System data to determine the location of the measurement being taken. Global Positioning System (GPS) data, which so many RF engineers have come to rely upon for outdoor measurement acquisition, is not an option for microcell environments. Therefore, recording real-time measurement data within a building becomes a laborious, time-consuming task involving scratched notes and blueprints and manual data entry which are both expensive and ineffectual in many respects.
In addition to measuring RF signal properties from emitted base transceivers there is also a need to measure data throughput time in computer data networks. Throughput time is the time required to transfer a record or file of known size from one computer to another. In order to standardize the measurement of data throughput time for comparison or verification purposes, files of a set size (e.g. 100K) are used and transferred in packet sizes such as 512 bytes. Similar to RF signal attenuation, data throughput time is also a function of transmission distance and signal obstruction (e.g. walls, doors, partitions), as well as multipath propagation and the specific radio modem design.
Various signal property measurement acquisition tools and systems have been developed to aid in the design of wireless communication systems such as PenCat(trademark), Walkabout PCS(trademark) and TEMS Light.
LCC International Inc. offers the PenCat(trademark) as a pen-based collection and analysis tool for wireless communication design that runs on a small hand-held tablet computer. The PenCat(trademark) system enables a user to roam about a building, take signal property measurement data at a location in the building using a receiver linked to the tablet computer, and link the measured data to that building location on a computer map representing the building by tapping the appropriate portion of the map on the computer screen with a stylus pen. The building map can be entered into the PenCat(trademark) system by either scanning blueprints, sketching the building within the application, or importing from another source.
Safco Technologies, Inc. offers the Walkabout PCS(trademark) system as a portable survey coverage system for use in indoor or outdoor wireless communication system design. Similar to PenCat(trademark), the Walkabout PCS(trademark) system utilizes a hand-held computer linked to a receiver for measuring signal properties at a given location and linking the measured property data to that location represented on a stored computer map.
Ericsson Radio Quality Information Systems offers the TEMS Light system as a verification tool for wireless communication indoor coverage. The TEMS Light system utilizes a Windows-based graphical interface on a mobile computer linked to a receiver to allow a user to view a stored building map, make location specific data measurements, and link the measured data to the represented location on the stored computer map.
In addition to the above-discussed wireless communication systems verification tools, various wireless communication system prediction tools have also been devised such as Wireless Valley Communications Incorporated""s Predictor(trademark) and Ericsson Radio Quality Information Systems"" TEMS. Predictor(trademark) allows a wireless communication system designer to predict the coverage area of a particular wireless system in a building or across multiple buildings. Predictor(trademark) creates a computer simulation using a computer stored building or facility database and a defined transceiver location and type within the database. Based on the building configuration and building material properties defined in the database a prediction of the coverage area of the wireless system is extrapolated by site-specific propagation whereby rays drawn between the transmitter and receiver and three-dimensional building information are used for prediction computations. The TEMS system predicts indoor coverage of a wireless system based on a stored building map and input base transceiver locations and types using statistical radio coverage models.
While the above-mentioned design and verification tools have aided wireless system designers in creating indoor wireless communication systems using building drawings and linking data measurements to building drawings, none of the devices, except Predictor(trademark), incorporate three-dimensional building drawings to enhance the design process. Further, the above-mentioned devices and systems lack the ability to track a roving user within the building while the user is taking measurement data. Even further, none of the above-mentioned devices contemplates measuring data throughput properties for a computer data network at various locations within a facility. These capabilities may be required for installation and management of wireless devices for global network access.
It is therefore an object of the present invention to facilitate measurement data acquisition for designing wireless communication systems within a facility.
It is another object of the present invention to scan, sketch, or import drawings of a facility into a computer to create a three-dimensional drawing database.
It is another object of the present invention to embed measured location-specific signal properties in a site-specific three-dimensional drawing database.
It is yet another object of the present invention to embed measured location-specific LAN data throughput properties in a site-specific three-dimensional drawing database.
It is still another object of the present invention to track a user within a building using a distance measuring mechanism and a stored site-specific three-dimensional drawing database.
It is yet another object of the present invention to average incoming measurement data over an interval of time or a unit distance.
The invention uses a three-dimensional drawing database of a facility and can position measured site-specific signal property information within a microcell environment using small, portable transceivers or receivers which continually report their measurement findings in real-time through a communication link with a computer (e.g., serial port, parallel port, or buffering circuit). The computer may be a personal computer, laptop, or other mobile computer. The process of taking in-building measurement data is then reduced to simply setting up a test transmitter at the selected facility site, configuring the transmitter within the three-dimensional drawing database, connecting the portable transceiver or receiver to the computer, and roaming throughout the three-dimensional drawing environment, identifying where the receiver is in the building at any given time by pointing and clicking within the drawing or employing a location tracking mechanism. A wheeled tracking mechanism is carried with a user and linked to the computer for measuring roaming distance between time intervals based on the number of wheel rotations. At each time interval the receiver location is identified, using the distance traveled by the tracking mechanism. Simultaneously, measurement data from the connected receiver is recorded, logged, and embedded directly in the three-dimensional drawing at the identified location. While the wheeled tracking mechanism is described in the preferred embodiment, other types of tracking or distance measuring devices can be used (e.g. laser range finder, sonar range finder).
An alternative to using a tracking device is to select a starting location in the stored three-dimensional facility drawing database and begin walking and measuring signal properties. Then select a stopping location once the walking and measuring process is stopped. Based on the starting and stopping locations the computer calculates a straight line path between the locations and distributes the measured data in one of several user specified formats. The user may specify that the measured data be distributed along the path at intervals of time, distributed along the path at units of length, or averaged and distributed along the path at units of length or time.
Using similar measurement acquisition methods described above the data throughput properties of a wireless computer data network can also be measured. This is accomplished by creating a link between a server computer and a mobile client computer, transferring a record of standardized size between the server and mobile client computer, and measuring the time required to transfer the record. This process can be carried out at a plurality of locations within a facility. At each location the measured time is recorded and embedded at the measurement location within a three-dimensional facility drawing database. Additionally, the server computer can also be mobile.
In addition to creating a three-dimensional database model and performing measurements in in-facility wireless communications and data networks the invention is capable of verifying the signal properties and data throughput properties of existing wireless communication and data networks.